The "Can't Stop This Feeling" singer shared a lengthy message to wife Jessica Biel to Instagram on Sunday afternoon, marking the actress's third Mother's Day celebration with son Silas Randall.

"I marvel at you," Justin captioned a rare photo of their little boy and Biel walking along the beach. "It's so hard to put into words EVERYTHING a Mother does. And, you do it with such grace. Thank you for giving me the greatest gift and continuing to show him what it means to be a good person in the world."

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He continued, "You make me realize how much my own Mother has done for me. #HappyMothersDay to you, my love. And, to my wonderful Mother and all the Moms all over the world: Y'all really DO RUN THIS... I bow down to you. --JT"

Jessica and Justin welcomed their 2-year-old bundle of joy in April 2015, three years after the longtime lovebirds tied the knot in 2012.

E! News recently caught up with the brunette beauty, where she couldn't help but gush about Silas and the impact he's made on her life. "I don't know if that sounds kind of goofy," Jessica said when reflecting on their son. "I just feel like I'm always ready for anything and everything at this point."

Motherhood "informs everything in your life," she added. "I'm more emotional, more sensitive, more everything to the world."